CLAIRTON, PA. -- For years, Danette Sprouse rested easily in the shadow of industry. Her front porch filled with coal dust and her nose burned from the pungent odors coming from the sprawling USS coke works here, but they seemed like small sacrifices compared to the high-paying jobs and comfortable lifestyle afforded by the plant.

Then Sprouse's 7-year-old son, Kirk, developed a rare type of cancer, forcing a reassessment. She began to wonder if the plant's emissions triggered the disease. She wondered why so many young cancer victims at Kirk's hospital came from the heavily industrialized Monongahela Valley. And she began to question whether any health sacrifice was too small for the sake of fostering industry.

"I can't believe anything is worth making a kid suffer," she said recently. "Do they have to make a huge profit every year when they're putting people at the risk of cancer?"

The question has arisen in many forms since the industrial revolution, but never so pointedly as in an ongoing congressional debate over emissions produced in the manufacture of coke, the basic fuel used to forge iron and steel that is made from coal cooked in 12-foot-high vaults. The House-Senate conference that for months has been trying to reconcile conflicting versions of the clean air bill is trying to sort out compelling but conflicting interests: protecting communities from the highest risk of cancer posed by any industrial activity versus protecting the well-being of an industry as essential as steel.

A larger issue is how far industry should be required to go to limit health risks to its neighbors. In the bills passed by both houses are emission standards for the production of coke based on health goals -- whether or not technology exists to meet them.

With strong advocates on both sides, the issue is one of the largest obstacles holding up agreement on a bill. Yesterday, conference staffers reached a tentative agreement on auto pollution, registering the first sign of progress in weeks.

The auto package, which must be approved by members of the conference, incorporates the weakest plan for curbing tailpipe emissions while accepting the toughest provisions for less polluting blends of gasoline.

The coke oven proposals are considered long overdue by neighbors of coke plants. Emissions from the ovens at Clairton gather in the broad valley and rain down on the little, hilly towns along the Monongahela River, eroding the aluminum siding of homes, killing gardens and often seeping into the hallways of the South Allegheny High School, choking students, according to residents.

Long a sacred cow of regulators and protected by the powerful steel caucus in Congress, the industry has successfully resisted federal controls on coke oven emissions for almost 20 years. And this year its message is blunt: Setting limits on cancer risks downwind of coke ovens would shut down nearly all of the nation's 40 plants, eventually halting steel production.

"It raises serious questions as to whether you can have any manufacturing or chemical industries in a high population area," said Philip X. Masciantonio, vice president of environmental affairs at USS in Clairton.

Even the industry concedes the need for top-notch technology to control the mustard-colored wisps of smoke that escape the 7-ton coke ovens. The House and Senate bills set limits on the number of leaking doors, differing slightly in degree of severity.

But the main fight in conference centers on a second round of controls to protect downwind communities from the cancer risks that remain after the technology is installed -- the so-called "residual risk."

Industry would be prohibited in both bills from exposing residents to a lifetime risk of cancer greater than 1 in 10,000. The Environmental Protection Agency recently adopted the ratio as a threshold for determining reasonable risk from airborne carcinogens. But with risk estimates for communities near several plants exceeding 1 in 100, the legislative goals are considered to be ambitious.

The bills differ in their timetables for implementation. The House treats coke oven emissions the same way as any airborne toxic, requiring that plants meet the residual risk standard as early as 2001.

But conference members have agreed privately to use the Senate bill as the vehicle for negotiation. The bill carved out special treatment for coke ovens, reflecting the strength of the steel caucus in that body. The residual risk requirement would be waived until 2020 for any plant that cuts back emissions to 3 percent of its doors by 1998. On the average, 10 percent of the coke oven doors used today leak.

Environmentalists criticize the waiver for unnecessarily prolonging high cancer risks for hundreds of thousands of people who live downwind of coke ovens. "They have a good chance of getting a cushier deal than any other industry, despite the fact that they're causing a higher cancer rate to more people than any other industry," said David Doniger of the Natural Resources Defense Council.

The USS plant here illustrates both the need for and obstacles to the legislation. The nation's largest coke plant -- its 800 ovens produce 4.5 million tons a year of coke to fire the furnaces of steel mills in four states -- the Clairton works is also one of the cleanest coke plants, having cut emissions 95 percent in the past decade. Only 4.5 percent of the coke oven doors leak on the average.

But because of its size and proximity to valley residents, Clairton has top ranking as a cancer risk, with odds of 1 in 55 for the most exposed individuals, according to a mathematical calculation by the EPA in 1989 that USS disputes. Given the huge disparity between Clairton's calculated risk and the 1-in-10,000 standard, Masciantonio said, the plant would have to close its doors even with the waiver.

Masciantonio said USS recognizes its responsibility to "do the very best that technology will enable you to do" to limit danger to its neighbors, but contends that the idea of eliminating risk in line with a mathematical model is utopian in a modern economy.

Danette Sprouse, 36, used to view risk similarly -- until her son got cancer.

"There's always risk," she said. "When you walk across the street, you can get hit by a car. I just don't think industry should be adding to the risks."